1. Field of the Invention
The present invention relates to an ink jet recording medium and a production process thereof.
2. Description of the Related Art
As a production process of an ink jet recording medium, it is known to form an ink receiving layer using alumina hydrate and polyvinyl alcohol as a binder and then subject the ink receiving layer to a cast treatment, thereby imparting high gloss to the ink receiving layer. Japanese Patent Application Laid-Open No. 2001-138628 discloses, as a cast treatment technique for achieving far excellent gloss, such an invention that a rewet cast treatment is conducted. As another cast treatment, a coagulating cast treatment is known, and such a method as described in Japanese Patent Application Laid-Open No. H09-059897 is disclosed.
In recent years, printing with not only a dye ink soluble in water but also a pigment ink in the form of being dispersed in water has increased. In particular, when printing is conducted with a pigment ink in which pigment is dispersed in water by a dispersant, gloss unevenness may occur between a printed area and an unprinted area in some cases, since the printed area to which the ink has been applied has a higher glossiness than the unprinted area to which no ink has been applied. In this case, a recording medium is required to have a higher glossiness to remedy the gloss unevenness, since the glossiness of the unprinted area depends on the recording medium. Thus, as a method for developing higher gloss using a casting method, Japanese Patent Application Laid-Open No. 2002-166645 discloses a method by adding fine particle colloidal silica into a coagulating liquid for coagulating cast treatment. Japanese Patent Application Laid-Open No. 2003-103914 discloses a method of improving gloss evenness by adding a cationic polyallylamine to a coagulating liquid.
On the other hand, as a method for realizing a high glossiness by another method than the cast treatment, there is known a method of developing a high glossiness by overcoating an ink receiving layer with fine particles or a resin compound. Japanese Patent Application Laid-Open No. 2005-246637 and Japanese Patent Application Laid-Open No. 2003-048371 disclose a method of enhancing glossiness by overcoating with a high-refractive index material and a method of enhancing glossiness by overcoating with a resin compound, respectively.